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Journal Articles: 48 results
The Use of Limits in an Advanced Placement Chemistry Course  Paul S. Matsumoto, Jonathan Ring, and Jia Li (Lily) Zhu
This article describes the use of limits in topics usually covered in advanced placement or first-year college chemistry. This approach supplements the interpretation of the graph of an equation since it is usually easier to evaluate the limit of a function than to generate its graph.
Matsumoto, Paul S.; Ring, Jonathan; Zhu, Jia Li (Lily). J. Chem. Educ. 2007, 84, 1655.
Acids / Bases |
Equilibrium |
Gases |
Mathematics / Symbolic Mathematics |
Thermodynamics
Flame Emission Spectrometry in General Chemistry Labs: Solubility Product (Ksp) of Potassium Hydrogen Phthalate  Frazier W. Nyasulu, William Cusworth III, David Lindquist, and John Mackin
In this general chemistry laboratory, flame emission spectrometry is used to determine the potassium ion concentration in saturated solutions of potassium hydrogen phthalate. From these data the solubility products, the Gibbs free energies of solution, the standard enthalpy of solution, and the standard entropy of solution are calculated.
Nyasulu, Frazier W.; Cusworth, William, III; Lindquist, David; Mackin, John. J. Chem. Educ. 2007, 84, 456.
Acids / Bases |
Atomic Properties / Structure |
Spectroscopy |
Equilibrium |
Quantitative Analysis |
Thermodynamics |
Titration / Volumetric Analysis |
Solutions / Solvents |
Aqueous Solution Chemistry |
Atomic Spectroscopy
Discovering the Thermodynamics of Simultaneous Equilibria. An Entropy Analysis Activity Involving Consecutive Equilibria  Thomas H. Bindel
This activity explores the thermodynamics of simultaneous, consecutive equilibria and is appropriate for second-year high school or AP chemistry. Students discover that a reactant-favored (entropy-diminishing) reaction can be caused to happen if it is coupled with a product-favored reaction of sufficient entropy production.
Bindel, Thomas H. J. Chem. Educ. 2007, 84, 449.
Acids / Bases |
Equilibrium |
Thermodynamics
Achieving Chemical Equilibrium: The Role of Imposed Conditions in the Ammonia Formation Reaction  Joel Tellinghuisen
The conditions under which chemical reactions occur determine which thermodynamic functions are minimized or maximized. This point is illustrated for the formation of ammonia in the ideal gas approximation using a numerical exercise.
Tellinghuisen, Joel. J. Chem. Educ. 2006, 83, 1090.
Gases |
Equilibrium |
Thermodynamics
Give Them Money: The Boltzmann Game, a Classroom or Laboratory Activity Modeling Entropy Changes and the Distribution of Energy in Chemical Systems  Robert M. Hanson and Bridget Michalek
Described here is a short, simple activity that can be used in any high school or college chemistry classroom or lab to explore the way energy is distributed in real chemical systems and as an entry into discussions of the probabilistic nature of entropy.
Hanson, Robert M.; Michalek, Bridget. J. Chem. Educ. 2006, 83, 581.
Equilibrium |
Statistical Mechanics |
Thermodynamics
Using Computer Simulations To Teach Salt Solubility. The Role of Entropy in Solubility Equilibrium  Victor M. S. Gil and João C. M. Paiva
Pairs of salts are discussed to illustrate the interpretation of their different behavior in water in terms of the fundamental concept of entropy. The ability of computer simulations to help improve students' understanding of these chemistry concepts is also examined.
Gil, Victor M. S.; Paiva, João C. M. J. Chem. Educ. 2006, 83, 170.
Computational Chemistry |
Equilibrium |
Thermodynamics |
Solutions / Solvents |
Precipitation / Solubility
Microscopic Description of Le Châtelier's Principle  Igor Novak
The analysis based on microscopic descriptors (energy levels and their populations) is given that provides visualization of free energies and conceptual rationalization of Le Châtelier's principle. The misconception "nature favors equilibrium" is highlighted.
Novak, Igor. J. Chem. Educ. 2005, 82, 1190.
Equilibrium |
Thermodynamics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems  Paul S. Matsumoto
While my paper states that the reaction quotient (Q) is not needed to solve equilibrium problems, it does not imply that Q is not valuable. In fact, when I teach this topic to my AP chemistry class, I initially use Q to solve the problem, then mention the alternative method described in the paper.
Matsumoto, Paul S. J. Chem. Educ. 2005, 82, 1150.
Equilibrium |
Learning Theories |
Mathematics / Symbolic Mathematics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems: No Problems with Q  Robert Lederer
Mr. Matsumotos students are to be congratulated for discerning an interesting mathematical procedure. Exclusively utilizing this algorithm, however, short-cuts the understanding of the chemistry involved. Students of chemistry should be challenged to understand why something occurs, and not to be satisfied with how to perform the often mundane calculations.
Lederer, Robert. J. Chem. Educ. 2005, 82, 1149.
Equilibrium |
Mathematics / Symbolic Mathematics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems: The Reaction Quotient (Q) IS Useful After All  Todd P. Silverstein
Paul Matsumoto was absolutely correct in writing The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems.
Silverstein, Todd P. J. Chem. Educ. 2005, 82, 1149.
Equilibrium |
Thermodynamics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems: The Reaction Quotient (Q) IS Useful After All  Todd P. Silverstein
Paul Matsumoto was absolutely correct in writing The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems.
Silverstein, Todd P. J. Chem. Educ. 2005, 82, 1149.
Equilibrium |
Thermodynamics
Playing-Card Equilibrium  Robert M. Hanson
A simple hands-on simulation suitable for either classroom use or laboratory investigation involves using a standard deck of playing cards to explore the statistical aspects of equilibrium. Concepts that can be easily demonstrated include fluctuation around a most probable distribution, Le Chtelier's principle, the equilibrium constant, prediction of the equilibrium constant based on probability, and the effect of sample size on equilibrium fluctuations.
Hanson, Robert M. J. Chem. Educ. 2003, 80, 1271.
Equilibrium |
Statistical Mechanics |
Thermodynamics
Le Chat: Simulation in Chemical Equilibrium  João C. M. Paiva, Victor M. S. Gil, and António Ferrer Correia
Software that illustrates Le Chatelier's principle; found on the Advanced Chemistry Collection CD-ROM, 3rd Edition.
Paiva, João C. M.; Gil, Victor M. S.; Correia, António Ferrer. J. Chem. Educ. 2003, 80, 111.
Equilibrium
Rubber Bands, Free Energy, and Le Châtelier's Principle  Warren Hirsch
Using a rubber band to illustrate Gibbs free energy, entropy, and enthalpy.
Hirsch, Warren. J. Chem. Educ. 2002, 79, 200A.
Noncovalent Interactions |
Thermodynamics |
Equilibrium
The Relative Acidities of Water and Methanol  Henry I. Abrash
Analysis of the disparity between the way the acidity constant of water is presented in general chemistry and organic chemistry textbooks.
Abrash, Henry I. J. Chem. Educ. 2001, 78, 1496.
Acids / Bases |
Equilibrium
Determination of Ksp, ΔG0, ΔH0, and ΔS0 for the Dissolution of Calcium Hydroxide in Water: A General Chemistry Experiment  William B. Euler, Louis J. Kirschenbaum, and Ben Ruekberg
This exercise utilizes low-cost, relatively nonhazardous materials presenting few disposal problems. It reinforces the students' understanding of the interrelationship of solubility, Ksp, ΔG0, ΔH0, and ΔS0.
Euler, William B.; Kirschenbaum, Louis J.; Ruekberg, Ben. J. Chem. Educ. 2000, 77, 1039.
Equilibrium |
Thermodynamics |
Titration / Volumetric Analysis
Simulations for Teaching Chemical Equilibrium  Penelope A. Huddle, Margaret Dawn White, and Fiona Rogers
This paper outlines a systematic approach to teaching chemical equilibrium using simulation experiments that address most known alternate conceptions in the topic. Graphs drawn using the data from the simulations are identical to those obtained using real experimental data for reactions that go to equilibrium. This allows easy mapping of the analogy to the target.
Huddle, Penelope Ann; White, Margaret Dawn; Rogers, Fiona. J. Chem. Educ. 2000, 77, 920.
Equilibrium |
Learning Theories
LeChâtelier's Principle in the Sciences  Volker B. E. Thomsen
The concept of homeostasis in biology and the economic law of supply and demand are both equilibrium-like principles, but involve systems in the steady state. However, all these principles involve the stability of the system under consideration and the analogies presented may be useful in the teaching of LeChtelier's principle.
Thomsen, Volker B. E. J. Chem. Educ. 2000, 77, 173.
Equilibrium |
Learning Theories
What Should We Teach Beginners about Solubility and Solubility Products?  Stephen J. Hawkes
Solubility equilibria are best taught qualitatively in introductory chemistry, leaving the calculations to higher level courses.
Hawkes, Stephen J. J. Chem. Educ. 1998, 75, 1179.
Solutions / Solvents |
Equilibrium |
Precipitation / Solubility
Chemical Equilibrium (the author replies)  Banerjee, Anil
Item 7 deserves a fuller answer than was provided.
Banerjee, Anil J. Chem. Educ. 1996, 73, A262.
Equilibrium |
Thermodynamics
Chemical Equilibrium  Logan, S. R.
Item 7 deserves a fuller answer than was provided.
Logan, S. R. J. Chem. Educ. 1996, 73, A261.
Equilibrium |
Thermodynamics
Thermodynamics and Spontaneity  Raymond S. Ochs
Despite the importance of thermodynamics as the foundation of chemistry, most students emerge from introductory courses with only a dim understanding of this subject.
Ochs, Raymond S. J. Chem. Educ. 1996, 73, 952.
Thermodynamics |
Learning Theories |
Equilibrium
Teaching Chemical Equilibrium and Thermodynamics in Undergraduate General Chemistry Classes  Anil C. Banerjee
Discussion of the conceptual difficulties experienced by undergraduates when dealing with equilibrium and thermodynamics, along with teaching strategies for dealing with these difficulties.
Banerjee, Anil C. J. Chem. Educ. 1995, 72, 879.
Equilibrium |
Thermodynamics
Equilibrium Calculator  Allendoerfer, Robert
The equilibrium calculator can calculate the equilibrium concentrations of all reagents in an arbitrary chemical reaction with as many as five reactants and products.
Allendoerfer, Robert J. Chem. Educ. 1993, 70, 126.
Equilibrium |
Chemometrics
The use of equilibrium notation in listings of standard potentials.  Donkersloot, Maarten C. A.
The difficulty in equilibrium notation of standard electrode potentials is due to the convention that half-reactions must be written as reductions if the given potential is to be called a (standard) electrode potential.
Donkersloot, Maarten C. A. J. Chem. Educ. 1992, 69, 256.
Equilibrium |
Electrochemistry
Standard states for water equilibrium (author response).  Campbell, Mark L.; Waite, Boyd A.
For the purposes of comparison only the unconventionally derived Ka values should be used to compare equilibrium constants for other acids to determine relative acid strengths.
Campbell, Mark L.; Waite, Boyd A. J. Chem. Educ. 1992, 69, 256.
Water / Water Chemistry |
Equilibrium |
Brønsted-Lowry Acids / Bases
Standard states for water equilibrium.  Baldwin, W. George; Burchill, C. Eugene.
The authors consider that Ka and Kb values for Bronsted acids and bases in aqueous solution represent one data set describing the properties of solutes in dilute aqueous solution.
Baldwin, W. George; Burchill, C. Eugene. J. Chem. Educ. 1992, 69, 255.
Water / Water Chemistry |
Equilibrium |
Brønsted-Lowry Acids / Bases
Chemical equilibrium: I. The thermodynamic equilibrium constant  Gordus, Adon A.
This is the first article in a series of eight that investigates the various assumptions that result in the simplified equilibrium equations found in most introductory texts. In this first article, the author considers the general nature of the constant K, Le Chatelier's principle, and the effect of the temperature on K.
Gordus, Adon A. J. Chem. Educ. 1991, 68, 138.
Thermodynamics |
Equilibrium
Calculating equilibrium concentrations by the continuation method  Cobranchi, Daryl P.; Eyring, Edward M.
The use of the continuation method allows the educator to both present more challenging equilibria to the students and to introduce students to another use for a personal computer.
Cobranchi, Daryl P.; Eyring, Edward M. J. Chem. Educ. 1991, 68, 40.
Equilibrium
Overall chemical equations  Gil, Victor M. S.
An equation sum can be used safely by itself in stoichiometric and equilibrium calculations only if the intermediates produced in separate reactions are at low steady-state concentrations and if there are no other equilibria involving those species.
Gil, Victor M. S. J. Chem. Educ. 1989, 66, 324.
Stoichiometry |
Equilibrium
A simple explanation of the salt water oscillator  Noyes, Richard M.
Yoshikawa et al. have described a simple device that undergoes repeated oscillations and that can also illustrate some of the principles essential to the oscillators driven by chemical reactions.
Noyes, Richard M. J. Chem. Educ. 1989, 66, 207.
Laboratory Equipment / Apparatus |
Thermodynamics |
Equilibrium
Thermodynamic changes, kinetics, equilibrium, and LeChatelier's principle  Hansen, Robert C.
A series of demonstrations in which water in beakers and the flow of water between beakers is used to represent the components of an exothermic chemical reaction and the flow and quantity of thermal energy involved in chemical changes.
Hansen, Robert C. J. Chem. Educ. 1984, 61, 804.
Equilibrium |
Kinetics |
Thermodynamics
On the misuse of Le Châtelier's principle for the prediction of the temperature dependence of the solubility of salts  Bodner, George M.
Explores why Le Châtelier's principle often fails to predict the temperature dependence of the solubility of salts.
Bodner, George M. J. Chem. Educ. 1980, 57, 117.
Equilibrium |
Precipitation / Solubility |
Solutions / Solvents |
Aqueous Solution Chemistry
Strong and weak acids and bases  Deck, Joseph C.
The designations "strong" and "weak" are used in various ways, and often with respect to the same compound in different situations.
Deck, Joseph C. J. Chem. Educ. 1979, 56, 814.
Acids / Bases |
Equilibrium |
Aqueous Solution Chemistry
An apparent contradiction in the application of the principle of Le Chtelier  Mellon, E. K.
Unless some care is exercised, the application of free energy concepts in situations where marked temperature changes occur can lead to apparent contradictions like the one described in this paper.
Mellon, E. K. J. Chem. Educ. 1979, 56, 380.
Equilibrium |
Thermodynamics
Minimizing the free energy: a computer method for teaching chemical equilibrium concepts  Heald, Emerson F.
This paper presents an alternative method to the standard treatment of equilibrium which uses material balance conditions and the minimization of the free energy. Both concepts are often omitted or glossed over in introductory treatments of equilibrium.
Heald, Emerson F. J. Chem. Educ. 1978, 55, 641.
Equilibrium
On mole fractions in equilibrium constants  Delaney, C. M.; Nash, Leonard K.
Proposes a hybrid equilibrium constant for use in introductory chemistry courses.
Delaney, C. M.; Nash, Leonard K. J. Chem. Educ. 1977, 54, 151.
Equilibrium |
Stoichiometry |
Aqueous Solution Chemistry |
Solutions / Solvents
The equilibrium between a solid solution and an aqueous solution of its ions  Berndt, Alan F.; Stearns, Robert I.
It is the purpose of this paper to present the equations that describe the equilibrium between solid solutions and their ions and to outline methods for their derivation.
Berndt, Alan F.; Stearns, Robert I. J. Chem. Educ. 1973, 50, 415.
Equilibrium |
Solutions / Solvents |
Aqueous Solution Chemistry
Chemical equilibrium (Nyman, Carl J.; Hamn, Randall E.)  Jekel, Eugene C.

Jekel, Eugene C. J. Chem. Educ. 1970, 47, A132.
Equilibrium
Le Chtelier and ionic equilibria  Ringbom, Anders
When s solution contains several weak acids, the squares of the separately calculated hydrogen ion concentrations of all weak acids in the solution are additive.
Ringbom, Anders J. Chem. Educ. 1968, 45, 442.
Equilibrium |
Acids / Bases |
Precipitation / Solubility |
Solutions / Solvents
A simple analogy of the relationship of ?G to the position of equilibrium  Marks, D. J.
This short note describes a simple demonstration to serve as an analogy of the relationship of ?G to the position of equilibrium.
Marks, D. J. J. Chem. Educ. 1967, 44, 402.
Thermodynamics |
Equilibrium
Principles of chemical equilibrium (Morris, Kelso B.)  Eblin, Lawrence P.

Eblin, Lawrence P. J. Chem. Educ. 1966, 43, 110.
Equilibrium |
Enrichment / Review Materials
Concerning equilibrium, free energy changes, LeChatelier's Principle. III. Halide-halate equilibria  Eberhardt, William H.
Compares four equilibria: KI + KIO3, KI + KBrO3, KBR + KBrO3, and KBr + KIO3.
Eberhardt, William H. J. Chem. Educ. 1964, 41, A883.
Equilibrium |
Aqueous Solution Chemistry |
Thermodynamics
Concerning equilibrium, free energy changes, Le Châtelier's principle II  Eberhardt, William H.
This demonstration involves a reversible, temperature-based transformation from blue tetrahedrally coordinated Co2+ to pink sixfold coordinated Co2+.
Eberhardt, William H. J. Chem. Educ. 1964, 41, A591.
Equilibrium |
Thermodynamics |
Aqueous Solution Chemistry |
Coordination Compounds
Concerning equilibrium, free energy changes, Le Chtelier's principle  Eberhardt, William H.
Aqueous KI is added to a solution of CuSO4 in a separatory funnel; adding more CuSO4 demonstrates an equilibrium sift.
Eberhardt, William H. J. Chem. Educ. 1964, 41, A477.
Equilibrium |
Thermodynamics |
Reactions
Temperature dependence of equilibrium: A first experiment in general chemistry  Mahan, Bruce H.
This experiment uses cooling curves to derive the expression for the temperature dependence of the equilibrium constant.
Mahan, Bruce H. J. Chem. Educ. 1963, 40, 293.
Equilibrium |
Thermodynamics
Textbook errors: Guest column. The solubility product constants of the metallic sulfides  Waggoner, William H.
This report reviews direct and indirect methods for investigating the solubility of substances, including conductance, potentiometric, optical, equilibrium, and thermodynamic procedures.
Waggoner, William H. J. Chem. Educ. 1958, 35, 339.
Precipitation / Solubility |
Equilibrium |
Metals |
Conductivity
Textbook errors: Guest column. XVI: The vapor pressure of hydrated cupric sulfate  Logan, Thomas S.
Examines variability in the values of pressures of water vapor in equilibrium with pairs of cupric sulfate in hydrates quoted in the literature and texts.
Logan, Thomas S. J. Chem. Educ. 1958, 35, 148.
Phases / Phase Transitions / Diagrams |
Equilibrium